Exploratory inference of the ingestive behavior of pigs in the finishing phase in an air-conditioned environment.

The objective of this research is to apply exploratory analysis and modeling associated with abiotic factors, physiological and behavioral variables of swine in the semi-arid region. The experimental design used was completely randomized, in a 3 × 3 factorial scheme, randomly distributed in nine pens, with three animals. The behavior of the animals was recorded using images and analyzed within 10-min interval. The data analysis used was multivariate, using the clustering method (tree diagram) and principal component analysis (PCA), in order to establish the main predictors of swine ingestive behavior, using multiple linear regression models. The PCA showed satisfactory results, in which the lowest eigenvalue observed was 2.82 and the accumulated variance for the treatments ranged from 69.70 to 94% for the first two principal components. Through exploratory data analysis, it was possible to identify the relationship between biotic and abiotic factors with the ingestive behavior of pigs in the finishing phase. Based on the results of the multivariate analysis, the most promising predictor variables for estimating the regression models were determined. Adiabatic evaporative cooling associated with 18 h of light was the combination of factors with the best results, presenting models for eating and drinking behavior, i.e. a complete ingestive characterization.

On the adoption of stricter energy efficiency standards for residential air conditioners: Case study Guayaquil, Ecuador.

Space cooling is the fastest-growing energy end-use in buildings worldwide, and Ecuador is no exception. Nevertheless, the last update of the Minimum Energy Performance Standards (MEPS) for air conditioners was in 2013 (EER 3.2W/W); since then, no new standards have been proposed in Ecuador. This study is the first assessment of stricter MEPS and estimation of benefits for the consumers and society of the residential sector in Guayaquil, Ecuador. The life cycle cost, payback time, net present value, electricity savings, and CO2 mitigation are the outputs from the Policy Analysis Modeling System (PAMS) methodology followed. The analysis considers future economic scenarios until 2035. Also, a new engineering approach based on linear optimization defines ACs designs in compliance with the proposed MEPS at the lowest cost. Therefore we can avoid setting less ambitious energy-efficiency targets when efficiency options are limited in the market (this is the Ecuadorian case). The analyzed MEPS are those proposed by UNEP and by the renewal program of inefficient equipment of the Ecuadorian Government. Our estimates show that AC demand can reach 17.3% of the total residential electricity demand in the business-as-usual scenario and 21.4% in the high economic growth scenario until 2035. Furthermore, the results show a significant gap between the proposed MEPS which can be progressively bridged. The best standard from the consumer perspective is EER 4.3W/W, while from the societal perspective, it is EER 5.5W/W. Stricter MEPS can reduce AC electricity demand and energy-related emissions between 5.7% and 31%, depending on the selected scenario. Therefore, stricter MEPS for AC represents a cost-effective option to reduce energy needs and emissions from air conditioners and a concrete action to support the national energy efficiency policies and nationally determined contributions for the residential sector.

Experimental air conditioning energy evaluation under Caribbean climate conditions.

A 23 factorial design was performed to analyze the performance of a mini-split air conditioning system under several psychrometric air conditions at the evaporator inlet, similar to Tropical Caribbean region conditions. In addition, a search for new energy-saving opportunities was performed. The results showed that interactions between the temperature of the air inlet, the humidity of the air inlet, and the fan speed level are significant in the mini-split energy performance under Caribbean climate conditions. Hence, working on an oriented energy savings control strategy is necessary. Therefore, this study recommends developing a fan speed control scheme, generating energy savings of around 10% in the air conditioning unit.

Future assessment of the impact of the COVID-19 pandemic on the electricity market based on a stochastic socioeconomic model.

This paper proposes a time-series stochastic socioeconomic model for analyzing the impact of the pandemic on the regulated distribution electricity market. The proposed methodology combines the optimized tariff model (socioeconomic market model) and the random walk concept (risk assessment technique) to ensure robustness/accuracy. The model enables both a past and future analysis of the impact of the pandemic, which is essential to prepare regulatory agencies beforehand and allow enough time for the development of efficient public policies. By applying it to six Brazilian concession areas, results demonstrate that consumers have been/will be heavily affected in general, mainly due to the high electricity tariffs that took place with the pandemic, overcoming the natural trend of the market. In contrast, the model demonstrates that the pandemic did not/will not significantly harm power distribution companies in general, mainly due to the loan granted by the regulator agency, named COVID-account. Socioeconomic welfare losses averaging 500 (MR$/month) are estimated for the equivalent concession area, i.e., the sum of the six analyzed concession areas. Furthermore, this paper proposes a stochastic optimization problem to mitigate the impact of the pandemic on the electricity market over time, considering the interests of consumers, power distribution companies, and the government. Results demonstrate that it is successful as the tariffs provided by the algorithm compensate for the reduction in demand while increasing the socioeconomic welfare of the market.

Pre-cooling water applied to porous plates of evaporative cooling systems / Efeito do pré-resfriamento da água aplicada em placas porosas de sistemas de resfriamento evaporativo

This study assessed the ways the thermal environment is influenced by pre-cooling the water employed in wetting the porous plates present in the evaporative cooling systems (ECS). The experiment was performed using two physical models constructed on a distorted and reduced scale, which simulated closed agricultural facilities equipped with ECS made up of porous cellulose panels. In one physical model, the plates were made wet using chilled water (ECScw), while in the other they were moistened using natural water, at environment temperature (ECSnw). Both inside the physical models and outside, in the external environment, the air dry-bulb temperature (tdb), black globe temperature (tbg) and air relative humidity (RH) were measured, at 10 sec intervals. Later, the environmental indices, ECSnw cooling effectiveness and ECScw performance factor were assessed. When the porous ECS plates were thoroughly wet using pre-cooled water, lowering of the thermal variables and comfort indices was seen to be greater than when wetting the plates was done using water at room temperature. An empirical equation was proposed to determine the cooling performance factor applied to the ECScw related to water temperature, tdb and air wet-bulb temperature.

Objetivou-se com o presente trabalho avaliar o efeito do pré-resfriamento da água usada no molhamento de placas porosas de sistemas de resfriamento evaporativo (SRE) sobre o ambiente térmico. O experimento foi realizado em dois modelos físicos construídos em escala reduzida e distorcida que simularam instalações agrícolas fechadas, equipadas com SRE composto por painéis porosos de celulose. Em um modelo físico, o molhamento das placas foi realizado por meio de água resfriada (SRAR) e o outro por meio de água natural à temperatura ambiente (SRAN). Mensurou-se a temperatura de bulbo seco do ar (tbs), temperatura de globo negro (tgn) e umidade relativa do ar (UR) no interior dos modelos físicos e no ambiente externo em intervalos de 10s. Posteriormente, foram calculados índices ambientais, a efetividade de resfriamento do SRAN e fator de desempenho do SRAR. O pré-resfriamento da água usada no molhamento de placas porosas de SRE propiciou maior redução nas variáveis térmicas e índices de conforto em relação ao molhamento com água à temperatura ambiente, sendo proposta uma equação empírica para a estimativa do fator de desempenho de resfriamento aplicada ao SRAR em função da temperatura da água, da tbs e da temperatura de bulbo úmido do ar.

Application of the Second Law of Thermodynamics in Brazilian Residential Appliances towards a Rational Use of Energy.

This article proposes the utilization of the concepts of destroyed exergy and exergy efficiency for equipment and process performance indicators that are related to the current energy planning scenario in Brazil, more specifically with energy-efficiency labelling. Several indicators associated with these concepts are discussed, including one national program that is based on labeling the energy efficiency of several residential, commercial and industrial appliances. The grades are indicated in the equipment using values from A to G. This labeling system is useful for discriminating similar technologies used for the same function; nevertheless produced by different enterprises. For this complementary analysis, two types of refrigeration methods were compared, absorption and vapor compression; however, these energy indexes alone are not sufficient parameters to select among these two technologies, because their performance indexes definition are different. To address this, our research considers the second law of thermodynamics through exergy analysis as a proper sub-index to obtain a systematic comparison between these various indicators. It is significant to highlight that seldom research studies addressed to this problem so explicitly, in an actual governmental working solution, aiming at discussing to the society the advantage of the usage of the "quality of the energy" as a complementary index to governmental and personal choices. Results indicate that it is possible to use the destroyed exergy and exergy efficiency to help select the technology that better utilizes natural resources, considering the energy matrix of the country. Appliances for water heating and air conditioning were compared from energy and exergy viewpoint, where the last gave additional information about the quality of energy conversion process, giving a completely different trend from the energy analysis alone, without the necessity to think about the energy matrix. Later this issue is addressed from both points of view. Future studies may suggest an exergy based index. The energy efficiency suggests that electrical shower (values higher than 95%) are better than gas water heaters (83% ) in using natural resources, whereas the exergy efficiency shares similar magnitudes (about 3%). A related pattern is shown for the theoretical air conditioning systems. The vapor compression systems have an energy index higher than 3, and absorption systems lower than 1. For these circumstances, the exergy efficiency shows figures nearby 30%.

Particle and Carbon Dioxide Concentration Levels in a Surgical Room Conditioned with a Window/Wall Air-conditioning System.

One of the most important functions of air conditioning systems in operating rooms is to protect occupants against pathogenic agents transported by air. This protection is done by simultaneously controlling the air distribution, temperature, humidity, filtration and infiltration from other areas etc. Due to their low price, simple installation, operation and maintenance, window/wall air conditioning system have largely been used in operating rooms in Brazil, even if these types of equipment only recirculate the air inside the room without appropriate filtration and renovation with outdoor air. In this context, this work aims to analyse the performance of the window/wall air conditioning systems on indoor air ventilation in operating rooms by measuring particle number concentrations and carbon dioxide concentrations during different surgical procedures, in a single surgical room and in the nearby areas (corridor) for two cases: single surgery and two subsequent surgeries. In addition, the efficiency of the analysed air conditioning system was evaluated by comparing the ventilation level calculated in the surgical room with the ventilation required in order to maintain the carbon dioxide concentration within acceptable levels. The results showed that this type of air conditioning system is not appropriate for use in operating rooms since it cannot provide an adequate level of ventilation. The CO2 concentrations during surgeries, in fact, significantly exceeded acceptable values and a simultaneous increase in particle number concentration was observed. The results also showed that there is a high risk of contamination between subsequent surgeries in the same surgical room, due to residues of contaminants transported by the particles emitted during the surgeries that were not removed from the operating room by the air conditioning system. The particle number concentration measured in the second surgery, in fact, was approximately six times higher than in the first surgery.

Thermal sensation in outdoor urban spaces: a study in a Tropical Savannah climate, Brazil.

The present study carried out assessments regarding thermal sensations under different weather conditions in three urban areas in Cuiabá, Brazil, a Tropical Savannah climate (Aw) region. Thermal acceptability by means of thermal sensation votes (TSV) was addressed based on the estimation of the Universal Thermal Climate Index (UTCI) values. Important issues related to clothing thermal insulation (Icl), the effect of gender on thermal sensation, and implications of artificial conditioning (AC) systems are also evaluated. Micrometeorological variables were determined and 685 questionnaires were applied to evaluate individual pedestrian thermal preferences. The Icl observed in the Tropical climate was lower than that intrinsically inputted by the UTCI for Temperate climates. The local thermal comfort zone ranged between 21.5 and 28.5 °C, with both thresholds higher than those observed in studies conducted in Subtropical, Mediterranean, and Continental Temperate climates while the local hot thermal sensation categories were displaced at least 3 °C above than those for the aforementioned climates. The effect of gender on thermal sensation indicated that females are more sensitive to cold stress conditions than males, requiring higher Icl for temperatures below 28 °C. The physiological adaptation by continuous exposure to AC systems reduced the neutral temperature between AC and non-artificial conditioning system users (NAC) by 0.8 °C, with more intense differences in hot TSV ranges. This study reveals differences between stated TSV classes derived for other climates and those resulting from TSV declared by Savannah local residents, indicating that local thermal sensation scale for UTCI in an important key for environment planning.

Cooling Effectiveness of a Data Center Room under Overhead Airflow via Entropy Generation Assessment in Transient Scenarios.

Forecasting data center cooling demand remains a primary thermal management challenge in an increasingly larger global energy-consuming industry. This paper proposes a dynamic modeling approach to evaluate two different strategies for delivering cold air into a data center room. The common cooling method provides air through perforated floor tiles by means of a centralized distribution system, hindering flow management at the aisle level. We propose an idealized system such that five overhead heat exchangers are located above the aisle and handle the entire server cooling demand. In one case, the overhead heat exchangers force the airflow downwards into the aisle (Overhead Downward Flow (ODF)); in the other case, the flow is forced to move upwards (Overhead Upward Flow (OUF)). A complete fluid dynamic, heat transfer, and thermodynamic analysis is proposed to model the system's thermal performance under both steady state and transient conditions. Inside the servers and heat exchangers, the flow and heat transfer processes are modeled using a set of differential equations solved in MATLAB™ 2017a. This solution is coupled with ANSYS-Fluent™ 18, which computes the three-dimensional velocity, temperature, and turbulence on the Airside. The two approaches proposed (ODF and OUF) are evaluated and compared by estimating their cooling effectiveness and the local Entropy Generation. The latter allows identifying the zones within the room responsible for increasing the inefficiencies (irreversibilities) of the system. Both approaches demonstrated similar performance, with a small advantage shown by OUF. The results of this investigation demonstrated a promising approach of data center on-demand cooling scenarios.

ADAPTACIÓN DE UNA METODOLOGÍA PARA LOS PROCESOS DE ADQUISICIÓN DE SISTEMAS DE AIRE ACONDICIONADO EN SERVICIOS DE SALUD / ADAPTATION OF A METHODOLOGY FOR PROCUREMENT PROCESSES OF AIR CONDITIONING SYSTEMS IN HEALTH SERVICES / ADAPTAÇÃO DE UMA METODOLOGIA PARA OS PROCESSOS DE AQUISIÇÃO DE SISTEMAS DE AR CONDICIONADO NOS SERVIÇOS DE SAÚDE

La adquisición efectiva de tecnologías en salud está enfocada al mejoramiento de la calidad y eficiencia, en la prestación de los servicios de salud ya que es un proceso complejo. Dentro de este proceso se destacan la evaluación técnica y clínica. El objetivo de la evaluación de tecnologías en salud es recolectar, analizar y sintetizar información y conocimiento para contribuir a mejorar la toma de decisiones en la práctica médica y en las políticas de salud. En este trabajo se presenta una evaluación en procesos de adquisición de sistemas de aire acondicionado en servicios de salud, basada en la definición de variables en campos de evaluación; dichas variables cuantifican lo técnico y funcional del equipo en su entorno clínico y económico. De igual manera, se pretende impulsar en los departamentos de ingeniería clínica la implementación de metodologías de amplia aceptación y efectividad que tienen como objetivo primordial la adquisición de tecnologías en salud basados en la evidencia.

The effective acquisition of health technologies is focused on improving the quality and efficiency in the provision of health services as it is a complex process. Within this process the technical and clinical evaluation are highlighted. The objective of the health technology assessment is to collect, analyze, and synthesize information and knowledge to help improve decisionmaking in medical practice and health policy. This paper presents an evaluation process of acquiring air conditioning systems in health care facilities, based on the definition of variables into a field evaluation; these variables quantify the technical and functional team in their clinical and economic environment. Similarly, it is intended to promote in clinical engineering departments, the implementation of widely accepted methodologies and effectiveness that have, as its primary objective, the acquisition of technologies in evidence-based health.

A aquisição efetiva das tecnologias da saúde é focada na melhoria da qualidade e eficiência na prestação de serviços de saúde, pois é um processo complexo. Dentro deste processo se destaca a avaliação técnica e clínica. O objetivo da avaliação de tecnologias em saúde é coletar, analisar e sintetizar informações e conhecimentos para ajudar a melhorar a tomada de decisão na prática médica e a política de saúde. Neste trabalho se apresenta um processo de avaliação de aquisição de sistemas de ar condicionado nos serviços de saúde, com base na definição de variáveis no campo da avaliação; essas variáveis vão quantificar o técnico e o funcional do equipamento em seu ambiente clínico e econômico. Da mesma forma, pretende-se promover nos departamentos clínicos de engenharia a aplicação de metodologias amplamente aceitas e eficácia que têm como objetivo principal a aquisição de tecnologias em saúde baseada em evidências.

Characterization of Francisella species isolated from the cooling water of an air conditioning system.

Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems.

Characterization of Francisella species isolated from the cooling water of an air conditioning system

Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems..(AU)

Characterization of Francisella species isolated from the cooling water of an air conditioning system

Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems.

Estratégias de implantação dos controles ambientais para prevenir a disseminação da tuberculose hospitalar / Estrategias para la implementacion de controles ambientales en la prevencion de la propagacion de la tuberculosis en los establecimientos de salud / Strategies for implementation of environmental controls to prevent the spread of tuberculosis in health-care settings

A transmissão intra-hospitalar da tuberculose consisteemumproblemade saúde ocupacional, e as medidas de controleefetivas incluem os controles ambientais que visam prevenir a disseminação dessa doença e reduzir as partículasinfecciosas aéreas. Trata-se de um estudo descritivo, realizado como objetivo de descrever a estrutura necessária paraimplantar e operacionalizar uma unidade de isolamento para tuberculose com pressão negativa do ar. A unidade foiprojetada comumsistema de climatização comcontrole de temperatura de 22±2 oC, recirculação do ar, filtragem HEPA,20 trocas de ar por hora e pressão negativa. Após a reforma da unidade e a implantação dos controles ambientais,o funcionamento do isolamento respiratório foi monitorizado por 12 meses. As ocasiões em que a pressão negativase tornou neutra foram identificadas pelos manômetros nos quartos e nos filtros, indicando a saturação deles e suasubstituição. Em seguida, a pressão negativa foi restabelecida. O investimento para a implantação do isolamento foide 75 mil dólares e o custo mensal de manutenção, 550 dólares. A unidade requer gerenciamento apropriado paraassegurar a proteção dos profissionais da saúde e demais pacientes.

Thenosocomial transmission of tuberculosis is a seriousoccupational health problem.Aneffectiveprevention of this diseaseincludes environmental measures to avoid its dissemination and to reduce the amount of droplet nuclei in the air. It is adescriptive study that aimed to describe the necessary structure for the implementation of an isolation roomwith negativeair pressure for patients with tuberculosis. The units were projected with HVAC system with temperature control at 22±2ºC, air recirculation system, HEPA filters, twenty two air changes per hour and negative air pressure. After repairs and theimplementation of the environmental control the functioning of the respiratory isolation wasmonitored for 12months. Inthe event of the negative air pressure becoming neutral the manometers in the room would display the filters saturationlevel and the need for their replacement. Soon after that the negative air pressure could be restarted. The isolation unitimplementationrequiredaninvestmentofUS$75,000.00 being themonthly repaircostUS$550.00.Therespiratoryisolationunit requires specific management strategies so as to ensure the protection of healthcare workers and patients.

La transmisión intrahospitalaria de la tuberculosis es un problema de salud en el trabajo y las medidas efectivas decontrol incluyen controles ambientales destinados a prevenir la diseminación de la enfermedad y reducir la cantidadde partículas infecciosas en el aire. Este estudio se realizó con el objetivo de describir la estructura necesaria paraimplementar y operar una unidad de aislamiento para la tuberculosis con presión de aire negativa. La unidad fuediseñada con un sistema de climatización con control de temperatura de 22 ± 2 ° C, recirculación del aire, filtros HEPA,veinte cambios de airepor horaypresión negativa. Después del proceso de reforma e implementación de los controlesambientales, el funcionamiento del aislamiento respiratorio fue monitoreado durante doce meses. Las ocasiones enque la presión negativa se convirtió en neutra fueron identificadas por manómetros en las habitaciones y en los filtros,señalando saturación y necesidad de sustitución. En seguida, la presión negativa fue restablecida. La inversión parainstalar el aislamiento fue de U$S 75.000,00yel costodemantenimiento mensual es de U$S 550,00. La unidad requiereestrategias de gestión adecuadas para garantizar la protección de los profesionales de la salud y de los pacientes.

Aspectos de contaminação biológica em filtros de condicionadores de ar instalados em domicílios da cidade de Manaus - AM / Aspects of biological contamination in air conditioning filters installed in Manaus city houses (AM)

Este trabalho apresenta resultados da pesquisa de contaminação dos filtros de condicionadores de ar instalados no setor residencial da cidade de Manaus. A pesquisa foi realizada no âmbito do projeto CAEMA (Condicionadores de Ar, Energia e Meio Ambiente) que consistiu na troca de aparelhos de ar condicionado ineficientes por eficientes na zona urbana da cidade. Dos 500 condicionadores de ar retirados do sistema pelo projeto, foram selecionados 50 filtros (10 por cento) para a análise de contaminação biológica, tendo sido identificada uma enorme variedade de agentes prejudiciais à saúde humana, entre bactérias e fungos. A bactéria mais vezes identificada foi a Staphylococcus sp e o fungo mais freqüente foi o Penicillium sp. Também foi possível verificar, por meio de entrevistas telefônicas junto a 37 usuários desses equipamentos, a grande incidência de sintomas associados a problemas de insuficiente qualidade de ar nos ambientes residenciais. Circunstâncias que motivaram a oportunidade desta pesquisa também impossibilitaram a coleta das amostras por unidade de volume, com os condicionadores ainda em funcionamento. Esse fato não comprometeu os objetivos da pesquisa, de promover a reflexão sobre os cuidados com a correta limpeza dos condicionadores de ar residenciais.

This work presents the results of a research about the contamination caused by air conditioners filters that are installed in the residential area in Manaus. The research took place in the scope of CAEMA's project (Conditioning of Air, Energy and Environment), which one consisted in changing inefficient conditional air devices for efficient ones in the urban zone of the city. Amongst 500 air conditioners removed of the system by the project, 50 filters (10 percent) were selected for biological contamination analysis, having been identified an enormous variety of agents, like bacteria and fungus, that are harmful for human health. The most identified bacterium was the Staphylococcus sp and the fungus more frequent was the Penicillium sp. Also it was possible to verify, by telephonic interviews with 37 users of these equipments, the great incidence of symptoms associates to the insufficient air quality in residential environments. The circumstances that had motivated the chance of this research, had also disabled that the assemble could be made per volume unit, with the conditioners still working. This fact did not compromise the quality of the work, neither the objectives to promote one reflection about the cares with the correct cleanness of the residential air conditioners.